A system for monitoring arterial oxygen tension in sick newborn babies. The measurement of arterial oxygen tension (PaO2) has for some time now been regarded as an essential part of the management of newborn babies receiving oxygen therapy. A system for monitoring arterial oxygen tension by means of a catheter-tip transducer is described. Comparisons of the transducer output with PO2 obtained by blood sample analysis are discussed. Up to the present time the PaO2 of more than sixty sick newborn babies have been monitored using these transducers in the Neonatal Unit at University College Hospital. The results obtained with these transducers in the first eighteen babies are reported in detail and demonstrate the possibility of continuous, reliable measurement of PaO2 under routine clinical conditions.


Structural fluctuations in the steady state of muscular contraction. Recent studies of the intensity fluctuation spectra of coherent light scattered from striated muscle have demonstrated the existence of large scale fluctuations in position and polarizability at the level of the myofibrillar sarcomere and its major structural subunits during the steady state of contraction. The existence of these fluctuations implies a fluctuating driving force. Various possible fluctuating motions of the thick and thin filaments, A and I bands, and entire sarcomeres are described. The magnitude of the fluctuating forces associated with the making and breaking of cross bridges is estimated. A mechanical model is proposed for coupling structural elements of a single sarcomere to one another and for coupling myofibrillar sarcomeres to one another. It is shown that the fluctuating force generated by the spontaneous making and breaking of cross bridges in conjunction with the model accounts for some of the features of the observed intensity fluctuation spectra.


Energetics of active transport processes. Active sodium transport across epithelial membranes has been analyzed by means of linear nonequilibirium thermodynamics. In this formulation the rates of active sodium transport JNa and the associated metabolic reaction Jr are postulated to be linear functions of both the electrochemical potential difference of sodium--XNa and the affinity A (negative free energy) of the metabolic reaction of driving transport. Experimental studies in various epithelia demonstrate that both JNa and Jr (oxygen consumption) are indeed linear functions of XNa. Theoretical considerations and experimental studies in other systems suggest that likelihood of linearity in A as well. If so, A may be evaluated. Several observations indicate that the quantity A evaluated from the thermodynamic formalism does in fact reflect the substrate-product ratio of the metabolic reaction which supports transport. This is in contrast to measurements of mean cellular concentrations, which may not reflect conditions at the site of transport. Associated studies of isotope kinetics permit the distinction between effects on the permeability of the active and passive transport pathways. With these combined approaches, it may prove possible to characterize both the energetic and permeability factors which regulate transport. The formulation has been applied to an analysis of the mechanism of action of the hormone aldosterone.


Cross-bridge conformation as revealed by x-ray diffraction studies on insect flight muscles with ATP analogues. The effects of three ATP analogues, alpha,beta-methylene-ATP [ATP(alpha,beta-CH1)], adenosine 5'-0-(3-thiotrophosphate) [ATP(gamma-S)], and beta,gamma-amino-ATP [ATP(beta,gamma-NH)] at various concentrations and temperatures on the X-ray fiber diagrams of glycerinated flight muscles from a water bug (Lethocerus maximus) have been investigated. It is shown that the "relaxed" state can be obtained with all three analogues at high concentrations, the result being particularly clear with ATP(gamma-S). It is inferred that the binding of an ATP-like molecule suffices to produce the relaxed state. At low concentrations ATP(beta,gamma-NH) produces state intermediate between rigor and relaxed which is not simply a mixture of the two. The possible nature of the intermediate is discussed.


Functional organization of mitotic microtubules. Physical chemistry of the in vivo equilibrium system. Equilibrium between mitotic microtubules and tubulin is analyzed, using birefringence of mitotic spindle to measure microtubule concentration in vivo. A newly designed temperature-controlled slide and miniature, thermostated hydrostatic pressure chamber permit rapid alteration of temperature and of pressure. Stress birefringence of the windows is minimized, and a system for rapid recording of compensation is incorporated, so that birefringence can be measured to 0.1 nm retardation every few seconds. Both temperature and pressure data yield thermodynamic values (delta H similar to 35 kcal/mol, delta S similar to 120 entropy units [eu], delta V similar to 400 ml/mol of subunit polymerized) consistent with the explanation that polymerization of tubulin is entropy driven and mediated by hydrophobic interactions. Kinetic data suggest pseudo-zero-order polymerization and depolymerization following rapid temperature shifts, and a pseudo-first-order depolymerization during anaphase at constant temperature. The equilibrium properties of the in vivo mitotic microtubules are compared with properties of isolated brain tubules.


Heckathorn's disease: variable functional dificiency of antihemophilic factor (factor VIII). A family is described in which a syndrome resembling moderately severe classic hemophilia was apparently inherited as an X chromosome-linked trait. In two affected individuals, the titer of functional antihemophilic factor varied dramatically from time to time, while the conversion of prothrombin to thrombin was impaired in no apparent relationship to AHF functional activity. A transfusion of 200 ml of fresh-frozen plasma did not correct the serum prothrombin times in either patient. In vitro, the additions of 10% of normal plasma or serum or washed plain or frozen platelets also did not normalize the serum prothrombin times. No inhibitor could be demonstrated in the blood of either patient.  In one patient, RH, dissipation of infused cryoprecipitated AHF was abnormally slow, and, after an intensive course of transfusion of cryoprecipitate and whole blood, the titer of functional AHF remained at normal levels for at least 1 wk. The plasma of RH inhibited a human antibody against AHF in proportion to its titer of functional AHF (i.e., the defect was CRM-) despite the presence of relatively greater amounts of antigenic material recognized by heterologous antiserum. No qualitative abnormality of the AHF-like material in RH's plasma was identified. Inheritance of the abnormality appears superficially to be X chromosome-linked; on this assumption, three of four obligate carriers of the disorder were recognized by the presence of excess amounts of AHF-like antigens relative to AHF functional activity. This coagulation disorder has been designated Heckathorn's disease and may presage the discovery of other examples of hemophilia-related syndromes.


Clinical staging of chronic lymphocytic leukemia. A method of clinical staging of chronic lymphocytic leukemia (CLL) has been proposed which is based on the concept that CLL is a disease of progressive accumulation of nonfunctioning lymphocytes: stage O, bone marrow and blood lymphocytosis only; stage 1, lymphocytosis with enlarged nodes; stage II, lymphocytosis with enlarged spleen or liver or both; stage III, lymphocytosis with anemia; and stage IV:lymphocytosis with thrombocytopenia. Analysis of 125 patients. in the present series showed the following median survival times (in months) from diagnosis: stage 0, is greater than 150; stage I 101; stage II, 71; stage III, 19; stage IV, 19, The median survival for the entire series was 71 mo. The prognostic significance of the stage remained even after adjustment was made for age and sex. However, both sex and age were shown to be poor predictors of survival after adjustment for stage. The method of staging proved to be a reliable predictor of survival whether used at diagnosis or during the course of the disease. The proposed staging system was an equally accurate indicator for survival when applied to two other previously published studies of large series of patients


The effect of Hydrocortisone on the kinetics of normal human lymphocytes. Lymphocyte kinetic studies employing 51-chromium-labeled autologous lymphocytes were performed in nine normal volunteers in order to determine the effects of hydrocortisone administration on the recirculating versus the nonrecirculating intravascular lymphocyte pools. Following infusion of labeled cells, the recirculating portion of the labeled cells rapidly equilibrated with the total intravascular lymphocyte pool and the vastly larger total-body recirculating lymphocyte pool, so that by 1 hr following infusion 21.8% plus or minus 3.2% of the labeled lymphocytes were left in the circulation. Four hundred milligrams of intravenous hydrocortisone administered 24 hr after infusion of labeled cells caused a profound but transient lymphocytopenia which was maximal at 4 hr with return of lymphocyte counts to normal by 24 hr after injection. Concomitant with the lymphocytopenia there was a dramatic increase in lymphocyte specific activity (cpm per 10-6 lymphocytes), while the total lymphocyte-associated radioactivity remaining in the circulation was unchanged, indicating that corticosteroid administration depleted the unlabeled recirculating cells. As the lymphocyte counts returned to normal following hydrocortisone, the specific activity also returned to normal. These studies indicated that hydrocortisone administration caused a transient lymphocytopenia by a preferential depletion of the recirculating portion of the intravascular lymphocyte pool


Studies on pure red cell aplasia. VII. Presence of proerythroblasts and response to splenectomy: a case report. An 18-yr-old female with chronic active hepatitis developed a severe anemia due to a lack of red cell production. Her bone marrow showed many large proerythroblasts but an almost complete lack of more mature erythroblasts. Incubation of the marrow cells in a normal medium with erythropoietin concentrate led to increased erythropoiesis as indicated by the development of mature erythroblasts as well as a ninefold increase in hemoglobin synthesis. The patient's plasma was cytotoxic for erythroblasts. Following splenectomy, a remission of the disease occurred. This study indicates that in some cases the anemia associated with abundant marrow proerythroblasts and the absence of mature erythroblasts has the same pathogenesis as pure red cell aplasia and that splenectomy may be beneficial when there is a lack of response to immunosuppressive drugs.


Diffusion through the vessel wall of transmitter released by sympathetic stimulation. A fluorescence and Autoradiography study. The disposition of sympathetic transmitter within the wall of rat femoral and rabbit saphenous arteries has been studied during sympathetic stimulation. Using a histochemical fluorescence technique, sharply delineated bead-like fluorescent spots representing sympathetic nerve terminals were found at the adventitio-medial junction. In specimens excised during sympathetic nerve stimulation, the entire media was veiled by fluorescent material representing noradrenaline which had diffused into that layer after release. The localization of the nerve terminals in controls as well as diffusion of transmitter during stimulation in the rat femoral artery was corroborated by autoradiography of tritiated noradrenaline.


Effects of phenoxybenzamine and norepinephrine on transmitter release in the pulmonary artery of the rabbit. The effects of phenoxybenzamine and norepinephrine (NE) on the release of tritiated NE were studied in spiral strips of the rabbit pulmonary artery. Phenoxybenzamine increased the tritiated NE efflux induced by transmural stimulation at 4 Hz by a factor of three. The magnitude of this effect was inversely related to the frequency of stimulation. NE (2.5 times 10- minus 6 M) decreased the enhancing effect of short exposure but not long exposure to phenoxybenzamine, probably by surmounting the phenoxybenzamine blockade of the alpha-adrenergic receptors on the adrenergic nerve terminal. The transmitter output per pulse increased with the frequency from 4 to 16 HZ and decreased at 32 HZ. This evidence suggests that a negative feedback mechanism does operate in this vascular preparation but, probably because of the wide neuromuscular cleft, is less effective than in tissues with a narrower synaptic interval.


Uptake of 14C-angiotensin by canine cutaneous blood vessels. The uptake of 14C-angiotensin was studied in canine cutaneous blood vessels in vitro. T/M ratios of 14C were 0.4, 0.5, 0.8 and 1.5 after 7.5, 15, 30 and 60 min of incubation, respectively. The T/M of 14C-sorbitol, an extracellular marker, was 0.4. No difference in the T/M ratios of C14 was found between normal and chronically denervated vessels incubated with 14C-angiotensin; however, the uptake  of 3H-norepinephrine was markedly decreased in the denervated preparation. The 14C taken up by the vessels after 30 min of incubation appeared to comprise both intact angiotensin and metabolites. These results suggest that a small quantity of intact angiotensin may be bound by vascular tissue, but is not concentrated in adrenergic nerve endings.


Human greater and canine lateral saphenous veins. A morphologic and pharmacologic study. Canine lateral saphenous vein and human greater saphenous vein were studied together to detmine similarities and differences. Helical strips of both vessels contracted to norepinephrine with similar sensitivity. Canine veins developed more isometric tension than human veins treated similarly. Histological studies show canine veins to have little connective tissue and a single circular layer of smooth muscle. Human veins have much connective tissue and three layers of smooth muscle, an inner circular layer, middle longitudinal layer and outer circular layer.


Treatment of experimental vasogenic cerebral edema with benzopyrones. Vasogenic cerebral edema was induced in rabbits by cold injury. Benzopyrone treatment, started 15 min after freezing, significantly reduced both brain edema and the increased permeability of the blood-brain barrier. On the other hand benzopyrone-treatment was without any effect in cytotoxic brain edema induced in rats by triethyl tin poisoning.


Influence of high levels of DDT in the diet on liver microsomal estrogen metabolism in the laying hen. Two experiments were conducted with laying hens to evaluate the effect of technical grade DDT on estrogen metabolism by liver microsomes using an assay which measured the metabolism of estradiol-17beta-4-14C. In Experiment I feeding 500 ppm DDT in the diet had no significant effect on estrogen metabolism after 10 days. However, the metabolism was increased after 18 days and more than doubled after 51 days. In Experiment II hens were fed diets containing 0, 300, 600 or 1200 ppm DDT and estrogen metabolism by liver microsomes was examined at 0, 7, 14, 21 and 35 days. A significant increase in estrogen metabolism was seen at 14 days with the feeding of 600 or 1200 ppm DDT and at 21 days with 300 ppm DDT. The ability to metabolize estrogen reached a maximum increase of approximately two-fold in all hens fed DDT. This required 14 days when the birds were fed 1200 ppm DDT, 21 days when fed 600 ppm DDT and 35 days when fed 300 ppm DDT. The increase in estrogen metabolism caused by DDT was found to be dose and time dependent.


Toxicity of high dietary levels of DDT in laying hens. White Leghorn hens were fed diets containing 0, 300, 600, or 1200 ppm technical grade DDT for three 28-day periods. The 1200 ppm diet caused tremors and 33% mortality in the final period, but no gross toxicity symptoms were seen in birds fed the other diets. Egg production was decreased during the third period by 600 or 1200 ppm. Egg weight was decreased during the third period by 600 or 1200 ppm. Egg weight was decreased during the last two periods by 1200 ppm. Shell thickness was decreased in all three periods by feeding 600 or 1200 ppm DDT. Dietary DDT caused no change that could be detected by shell beta backscatter. Shell weight as a percent of total egg weight was decreased by 600 or 1200 ppm DDT.


Residues of quintozene, hexachlorobenzene, dichloran and pentachloroaniline in soil and lettuce. The results are described of the residue determination of quintozene, hexachlorobenzene, dichloran and pentachloroaniline in soil and lettuce after application of different quantities of quintozene just before and two weeks after planting. The results indicate that quintozene, hexachlorobenzene and dichloran are readily taken up by lettuce from the soil and that quintozene is metabolised to pentachloroaniline resulting in residues of these compounds in lettuce.


Analysis of free and bound chlorophenoxy acids in cereals. Extraction of the chlorophenoxy acids 2,4-D and dichlorprop in cereals has been examined by analyzing barley from spraying experiments. A procedure has been set up by combination of acid hydrolysis and enzymatic degradation followed by extraction and clean up on either silica gel or basic aluminum oxide. The final determination is based on reaction with diazomethane and subsequently GLC with ECD. This procedure was compared with two different extraction procedures previously described in the literature. The one comparative procedure uses a mixture of 50% diethyl ether/hexane in presence of sulphuric acid and resulted in residues up to ten times lower than found after the combined acid hydrolysis/enzymatic degradation procedure. In the second comparison a direct extraction was made with a mixture of 65% (v/v) acetonitrile in water. No differences were found between this and the combined acid hydrolysis/enzymatic degradation procedure.


Barbiturate potentiation in mercury poisoning. Barbiturate potentiation was observed in Japanese quail fed dietary levels of 4, 21, and 24 ppm Hg as methyl mercuric chloride. Gross symptoms of mercury poisoning were not observed until after BP was observed. After the initial increase in BP time was observed in the birds receiving 4 and 12 ppm mercury, there followed a plateau in response until those birds receiving 24 ppm Hg began to show gross symptoms of toxicity and the BP time markedly rose again. Pronounced BP persisted 7 weeks after removal of mercury from the diet reflecting the long biological half-life of mercury as the methyl derivative. Selenium effectively prevented BP after 7 days exposure to toxic levels of methyl mercury chloride. Therefore, results suggest that early toxic effects of mercury can be observed readily by BP and that this environmental contaminant may influence drug activity or increase the sensitivity of the nervous system to sodium pentobarbital.


The effects of subacute and chronic exposure to 4-aminopyridine on reproduction in coturnix quail. When male and female coturnix quail (Coturnix coturnix) were given a single subacute oral dose (5.62 mg/kg) of the avian frightening agent 4-aminopyridine (4AP) and paired with untreated mates, there was no effect on the reproductive performance of males; egg production of females was reduced the third week after treatment but recovered during the fourth week. Chronic exposure to 31.6, 100, and 316 ppm of 4AP in the diet of mated pairs did not affect reproductive performance during or after the 4- or 6-week period the chemical was fed, but no birds fed 1,000 ppm produced live chicks after treatment began and all died within 3 weeks. The 28-day LC50 of 4AP was determined to be 447 ppm for male coturnix and 562 ppm for females. F1 progeny from quail fed 31.6, 100, and 316 ppm 4AP and randomly mated at maturity showed no reproductive effects from their parents' exposure.


Operations of the Biblioteca Regional de Medicina (BIREME). The operations and accomplishments of the Biblioteca Regional de Medicina (BIREME), the regional medical library of the Pan American Health Organization, are summarized. Aspects of BIREME's program which are described include: strengthening biomedical collections in Latin America, network organization, international cooperation, document and information delivery, bibliographic services, and educational efforts.


MLA continuing education activities, 1964-1974: a decade of growth and development. The medical Library Association's present program of continuing education began with the presentation of courses at the annual meeting in San Francisco in 1964. Since that time the range and scope of the Association's continuing education activities have grown rapidly. This paper examines the growth of those activities, assesses the present role of the Committee on Continuing Education, and considers some of the implications of the proposed certification code on the work of the Committee on Continuing Education.


User needs: the key to changing library services and policies. A user survey and a series of faculty interviews are discussed as methods that can be used by a public relations librarian to change library policies and services in the direction of patrons' needs.


Medical Librarianship in Nigeria--a review of the literature and comments on some problems and prospects. The literature of medical librarianship of Nigeria is reviewed. The staff structure of Nigerian univeristy libraries and, in particular, of the medical libraries attached to them is restrictive, unprogressive, and unconducive to the development of medical librarianship in Nigeria. These medical libraries should cease to be administered and regarded as just unavoidable appendages of the main university libraries. They should be independent, full-fledged libraries of their own, recognixed as full academic departments of their respective colleges or faculties, with their heads being in no way inferior in status to other heads of academic departments. The granting of faculty status to Nigerian unviersity librarians should go the whole way and let the principle of multiple professorships be applied to the staff structure of unviersity libraries. Efforts are being made to effect bibliographic organization of Nigerian medical literature. A national library of medicine for Nigeria, however, humble its beginning, should be established.


Studies on the behavioural pharmacology of a cyclic analogue of dopamine following its injection into the brains of conscious rats. 1. The cyclic analogue of dopamine, 2-amino-6,7-dihydroxy-1,2,3,4-tetrahydronaphthalene (ADTN) was injected into the lateral ventricle or bilaterally into the nucleus accumbens or caudate nucleus of conscious rats and its effect on locomotor activity was investigated. 2. When given intraventricularly, ADTN produced some stereotyped responses which were followed by a strong and long lasting stimulation of locomotor activity. When administered bilaterally into the nucleus accumbens a similar stimulation of locomotor activity was observed. ADTN had no effect on locomotor activity when injected bilaterally into the caudate nucleus. 3. The ADTN-induced locomotor stimulation following its intraventricular injection was completely abolished by a low dose of pimozide (0.01 mg/kg, i.p.) or haloperidol (0.5 mg/kg, i.p.). Pimozide (1 mg/kg, i.p.) given 30 min before ADTN injected bilaterally into the nucleus accumbens completely blocked locomotor stimulation. 4. Unilateral injections of ADTN (5 mug) into the nucleus accumbens caused locomotor stimulation but no turning. 5. Bilateral injections into the nucleus accumbens of 2-amino-6,7-dimethoxy-1,2,3,4-tetrahydronaphthalene or 0.9 percent w/v NaCl solution had no effect on locomotor activity. 6. It is concluded that the central stimulant action of ADTN is due to an effect on the dopamine receptors in the nucleus accumbens.


Adrenoceptors in intracerebral resistance vessels. 1. The effects of tyramine and isoprenaline on hypothalamic blood flow (HBF) were measured in conscious rabbits. 2. Injections of small doses of tyramine caused an increase in HBF while larger doses caused a decrease in HBF. 3. Isoprenaline injections also produced an increase in HBF. 4. The vasodilatation induced by isoprenaline and the small dose of tyramine was blocked by propranolol. 5. The vasoconstriction induced by the larger doses of tyramine was abolished by phenoxybenzamine. 6. Chemical sympathectomy of the hypothalamus with 6-hydroxydopamine and depletion of biogenic amines by reserpine also abolished tyramine-induced vasocoonstriction. 7. These results suggest the presence of alpha- and beta-adrenoceptors in cerebral resistance vessels, and that these receptors may be activated by released (endogenous) noradrenaline.


The interaction of neuroleptic and muscarinic agents with central dopaminergic systems. 1. The effect of muscarinic and neuroleptic agents on the turning behaviour induced by methamphetamine and apomorphine in rats with unilateral lesions of the substantia nigra induced by 6-hydroxydopamine has been examined. 2. Turning towards the side of the lesion induced by (+)-methamphetamine (5 mg/kg) was inhibited by alpha-flupenthixol (1 mg/kg) and alpha-clopenthixol (8 mg/kg) but not by high doses of their beta-isomers. 3. Turning was inhibited by chlorpromazine (4 mg/kg) and pimozide (0.2 mg/kg). Thioridazine and clozapine (16 mg/kg) were ineffective. Turning in the same direction produced by scopolamine (10 mg/kg) was also inhibited by alpha-flupenthixol (1 mg/kg) and pimozide (0.25 mg/kg). 4. Turning produced by methamphetamine (5 mg/kg) was inhibited by oxotremorine (0.75 mg/kg) even in the presence of methylatropine (5 mg/kg). 5. Turning away from the side of the lesion induced by apomorphine (0.1 mg/kg) was inhibited by oxotremorine (0.75 mg/kg) but not by thioridazine or clozapine (16 mg/kg). 6. These results are discussed with regard to the mode of action of neuroleptic drugs in producing anti-psychotic effects and drug-induced Parkinsonism.


Hypothermic action of bromocriptine.

Hypothermic action of bromocriptine. The body temperature of rats has been studied in a cold environment. In this setting, bromocriptine induced hypothermia. This fall in core temperature was inhibited by pimozide. It was concluded that bromocriptine has a dopamine-like action in areas of the brain concerned with the control of body temperature, as has previously been shown for apomorphine and amphetamine.


Effect of clonidine on the excitability of vasomotor loci in the cat. 1. The effect of clonidine on the direct excitability of hypothalamic, medullary and spinal vasomotor loci has been investigated in cats anaesthetized with chloralose. 2. Clonidine inhibited the excitability of these loci when it was localized to the central sites by intracerebroventricular, intravertebral arterial or intrathecal injection in very low doses (1-2 mug). 3. Topical application of clonidine (0.01 percent and 1.0 percent) to the floor of the fourth ventricle inhibited pressor responses evoked either by stimulation of medullary or hypothalamic vasomotor areas. Inhibition of the pressor responses was accompanied by hypotension and bradycardia in many experiments. 4. It appears that effects of clonidine on the vasomotor loci of the medulla oblongata and the spinal cord contribute to its hypotensive action.


Local anaesthetic and antiarrhythmic properties of an aminosteroid: 3alpha-dimethyl-amino-5alpha-androstan-2beta-ol-17-one (Org. NA 13). 1. The aminosteroid Org. NA13 (3alpha-dimethylamino-5alpha-androstan-2beta-ol-17-one) was shown to be a more potent local anaesthetic than lignocaine in rats and guinea-pigs. 2. Experimental arrhythmias induced in mice by chloroform, in rats by aconitine and in dogs by coronary artery ligation were corrected by Org. NA13 at doses from 10 to 50 mg/kg intravenously. 3. In contrast to lignocaine, other local anaesthetics and beta-adrenoceptor blocking drugs, Org. NA 13 did not show any activity against the arrhythmias induced by ouabian in dogs. 4. The acute toxicity in whole animals and myocardial toxicity in the rabbit isolated atrium appeared to be less than that observed with lignocaine.


Effects of acute cocaine treatment on the turnover of 5-hydroxytryptamine in the rat brain. 1. The effects of cocaine (20 mg/kg s.c.) on 5-hydroxytryptamine (5-HT) turnover were examined in rats. 2. In vivo cocaine administration resulted in decreased turnover of 5-HT, as indicated by the decreased accumulation of 5-HT after pargyline administration and the decreased accumulation of 5-hydroxyindoleacetic acid (5-HIAA) following probenecid injection. 3. A time-related decrease in 5-HIAA concentrations and a small fall in 5-HT concentrations in the whole brain were observed following the acute administration of cocaine hydrochloride (20 mg/kg). Tryptophan levels were found to be slightly decreased in the brain. 4. Enhanced reactivity, but neither stereotypy nor hyperthermia, was observed following cocaine injection (20 mg/kg). 5. It is concluded that cocaine inhibits the turnover of brain 5-HT and that this action of cocaine may be responsible for the differences in a number of pharmacological effects between cocaine and amphetamine.


Studies on the positive inotropic effect of phenylephrine: a comparison with isoprenaline. 1. The effects of phenylephrine and isoprenaline on the isometric contraction of guinea-pig ventricle were compared over the whole range of their respective dose-response curves. 2. In preparations driven at 2.5 Hz the increase in contractile force induced by either isoprenaline of phenylephrine was linearly correlated to an increase in maximum velocity of force development. The relaxation time was shortened by isoprenaline but not by phenylephrine. 3. The negative inotropic effect induced by delta [N-(3,4-dimethoxyphenethyl)-N-methyl-amino]-alpha-(3,4,5-trimethoxyphenyl)alpha-isopropylvaleronitrile hydrochloride (D(600)) was reversed by isoprenaline, but little influenced by phenylephrine. 4. The study of the interval-force relationship shows that the increase in contractile force induced by phenylephrine (3 X 10(-5) M) was relatively greater at low frequencies of stimulation, and that the maximum effect was reached at the frequency of 1 Hz. 5. The positive inotropic effect of phenylephrine (10-4 M) was significantly higher at a frequency of 1 Hz than at 2.5 Hz; the effect of isoprenaline (3 x 10-8 M) was not significantly different at the two driving frequencies. 6. In preparations driven at 1 Hz the inotropic effect of the lower concentrations of phenylephrine was due to an increase in the time to peak tension without any change of the maximum velocity of force development; however an increase of this parameter became evident only after higher concentrations of the amine (10-5 M or more), associated with a progressive shortening of the time to peak. 7. A correlation between mechanical and electrophysiological effects of phenylephrine is attempted; the suggestion is advanced that the prolongation of the action potential and of the active state duration may be an important factor in the inotropic effect of phenylephrine.


Review article-Bone scanning.

Review article-Bone scanning. The discovery of a number of phosphate complexes labelled with 99-Tc-m that localize in bone has aroused wide-spread interest in bone scanning. The physiological properties of these and other clinically useful bone-seeking radiopharmaceuticals are compared, and their physical properties assessed in relation to the characteristics and limitations of avilable detector systems. A hypothesis is put forward to explain the behaviour of the technetium-labelled agents. It is concluded that although there are differences in biochemical behaviour between these agents, strontium and fluorine, all three may, under suitable conditions, give similar clinical information. The radiation dose received by the patients is least with the usual dose of 99-Tc-m and the blood clearance of the diphosphonate and pyrophosphate preparations is faster than that of strontium, although slower than fluorine. The psi-ray energy of technetium permits a much greater efficiency of detection than of fluorine. These factors, toghether with the general availability of 99-Tc-m and its relatively low cost make the technetium diphosphonate or pyrophosphate preparations the agents of choice for most skeletal radioisotope imaging. However, there are as yet insufficient follow-up studies to be able to assess the incidence of either false-negative or false-positive findings with these agents.


The posterior tracheal band: a reflector of local superior mediastinal abnormality. The posterior tracheal band (PTB)  is a thin band of uniform width consisting primarily of the posterior tracheal wall which is observed almost constantly in a well-positioned and exposed lateral view of the chest. It is formed by two interfaces; and internal junction line between the inner tracheal wall and air in the lumen, and an external junction line between the adventitial surface of the right posterior wall (with paper-thin mediastinal covering) and aerated lung in the right retrotracheal recess. Any pathological process in the mediastinum, pleura or right upper lobe medially which affects the external interface causes an alteration or disappearance of the PTB. Anatomical studies explaining the formation of the PTB and clinical cases showing its alteration or disappearance are presented.


The value of colour subtraction of angiograms particularly in cerebro-vascular disease. Eighty colour subtractions of cerebral angiograms have been analysed to assess their value in actual diagnosis, particularly of cerebrovascular disease. The method has been found to be so valuable, either for confirmation of the findings seen on the original angiograms or in providing new data about the accurate localization and nature of the lesion, that it has now become a routine for all cerebrovascular cases. A selection of cases is presented and the limitations of the method discussed.


Borderline variants of the normal pituitary fossa. Endocrinologists tend to accept minor variations of the pituitary fossa as evidence of the presence of a pituitary gland abnormality. Neuroradiologists tend to be sceptical. Normal criteria have not been established. In a consecutive series of 85 cases without any clinical evidence of a pituitary lesion, the plain films in 31.7 per cent demonstrated minor duplication of the floor or anterior wall of the pituitary fossa (with or without associated thinning and possible erosion of the lamina dura), which could be mistaken for the early signs of pituitary enlargement by an intrasellar tumour. 16.5 percent showed thinning of the lamina dura on tomography a feature previously taken as suggesting early enlargement. It is suggested that these particular diagnostic signs should be interpreted with caution.


The relation between sub-capital fracture of the femur and mineral content of the right third metacarpal. Positive correlation between the mineral content of the mid site of right third metacarpal and neck of femur has been established using the psi-ray absorption technique described by Shimmins et al. (1972b) to make measurements on excised human bones. An X-ray method (Anderson, Shimmins and Smith, 1966; Shimmins et al. 1972a) was used to measure the mineral content of the right third metacarpal in 101 female and 22 male patients with subcapital fracture of the ferum. When their metacarpal "whole bone densities" were compared with those of control subjects of the same age and sex, they were found to have significantly lower (P smaller than (0.025) average values. However, groups of patients defined according to Garden's classification of severity of fracture could not be distinguished one from the other on the basis of metacarpal whole bone density measurement.


Yttrium 90 in persistent synovitis of the knee - a single centre comparison. The retention and extra-articular spread of four 90-U radiocolloids. The characteristics of three colloidal preparations of 90-Y currently used for the irradiation of chronic synovitis of the knee have been studied. One, 99-Y silicate, showed less leakage away from the joint than the other two preparations, 90-Y ferric hydroxide and 90-Y citrate. Comparable amounts of 90-Y were taken up regional lymph nodes when the silicate and ferric hydroxide forms were used; the greatest irradiation of regional lymph-nodes occured using the citrate form. In this respect all three preparations are inferior to the previously used preparation 90-Y resin colloid which is no longer manufactured.


The radiosensitivity of a mesenchymal tissue. The pericryptal fibroblast sheath in the human rectal mucosa. With the exception of haemopoietic tissue quantitative studies of the effects of irradiation on replicating normal tissue call systems in vivo have previoulsy been confined to epitelial tissuss. A similar sheath of fibroblasts to that surrounding the crypts of Lieberkühn in the colon, which it is climed undergoes constant renewal and migration, has now been identified in the rectum and thereby it may become possible to follow the cellular response to irradiation of a mesenchymal tissue. The numbers and the distribution of the pericrytal fibroblasts in normal human rectum following irradiation, both in air and hyperbaric oxyge, have been stuided in serial biopsies of rectal mucosa taken from patients who were being treated for advanced pelvic maliganancies. The results indicate that during a course of irradiation the fibroblasts cell count falls on a time-scale very closely associated with that seen in the epithelial cells. Only some immediate recovery occurs in the fibroblast system, in contrast to the adjacent epithelial cell system where full recovery seems to take place. The fibroblast system, moreover, shows a gradually diminishing trend during the first year, whilst the epithelial cell numbers appear to be maintained. The interpretation of these data are discussed. Evidence is provided that when patients breath hyperbaric oxygen during irradiation more extensive depression of cell numbers occurs, but after recovery there is essentially no difference in the cell counts - finding that accord with those previously reported fro epithelial cells in the crypts of the rectal mucosa.


The relationship of the urinary cations, Calcium, Magnesium, Sodium and Potassium, in patients with Renal Calculi. Calcium, magnesium, sodium and potassium were estimated in the 24-hour urine collections of 101 idiopathic male stone-formers, 89 male patient controls and 59 young male adult controls. The results were calculated in terms of 24-hour volume and 1 g of creatinine. The concentrations of the 4 cations, relative to a gram of creatinine, were also determined in the early-morning urines of 41 male stone-formers and 13 young male adult controls. No difference was observed in the 24-hour excretion of calcium, magnesium and sodium between the stone-formers and controls. The mean daily potassium excretion, however, was significantly reduced in the urine of stone-formers. The linear regression equations were calculated for calcium on magnesium, calcium on sodium, and calcium on potassium, using the 24-hour excretion values of these cations. Only the calcium on potassium line of stone-formers was significantly different from that of the normal subjects. A significant increase by stone-formers in the urinary calcium concentration of their early-morning specimens was found. The high concentration of urinary calcium in overnight urines of stone-formers combined with a low magnesium concentration might possibly contribute to the development of renal stone disease.


Evaluation of differential renal function studies in segmental renal artery occlusion. 3 patients with suspected renal segmental ischaemia are presented. In 2 of them segmental renal artery stenosis was demonstrated radiographically and the differential renal function studies predicted the outcome of surgery accurately. In the last patient no segmental renal artery stenosis was demonstrated on angiography, and surgery did not benefit this patient in spite of positive differential renal function studies for "curable" renal segmental ischaemia. Some haemodynamic aspects, as expressed by the differential renal function studies, are discussed.


The radiological diagnosis of "avascular" renal tumours. In the past 9 years we have encountered 3 renal space-occupying lesions, which were "avascular" at arteriography but which appeared to be tumours, as shown by renal puncture of "antegrade" pyelography, All had an irregular inner border demonstrated. The investigation and radiological diagnosis of such masses is discussed thad compared with that of renalcysts.


Regression of Metastases after Nephrectomy for Renal Cell Carcinoma. A case of an extensive renal cell carcinoma with temporary regression of pulmonary metastases is reported. The literature of similar reported cases is brefly reviewed.


Ureterometrographic studies on human subjects with normal urinary tract system. Ureteral motility was studied in 40 subjects with normal urinary tract systems. Although the contraction waves were often monophasic in shape some were characterised by the presence of a notch on the contraction or relaxation limb of the peristaltic complex, indicating that notched complexes do not necessarily signify obstructive uropathy. Retrograde filling of the bladder to within its physiologic limits with isotonic saline solution markedly changed the pattern of the ureteral activity.


Urinary diversion: the physiological rationale for non-refluxing colonic conduits. In order to make an accurate comparison between ileal and colonic conduits, and ileal conduit was created from one kidney and a non-refluxing colonic conduit from the other kidney in 16 adult mongrel dogs. Colonic loops do not reflux, have equal resting pressures and rate of emptying when contrasted with ileal conduits, and carry a lower incidence of stomal complications. Colonic conduits respond more favourably to acute occlusion and produce a significantly lower rate of pyelonephritis at 3 months. These factors suggest that colonic conduits offer a definite advantage for long-term urinary diversion.


Kaposi's sarcoma of the penis.

Kaposi's sarcoma of the penis. The 11th case of Kaposi's sarcoma of the glans penis is reported. Aetiology and treatment are discussed and evidence adduced to support a conservative surgical approach by local excision, supplemented if necessary by low dosage irradiation and possibly methotrexate infusion.


Leiomyosarcoma of penis--case report and review of the literature. A case of low-grade leiomyosarcoma of the penis is described. The patient was treated by partial amputation, and is alive and free of recurrence for 6 months. Ten other previous cases are reviewed and discussed.


Sarcoidosis of the penis treated by radiotherapy. A case of sarcoidosis of the penis is reported which initially caused ulceration around the external urethral meatus. After an immediate response to steroid therapy, the disease recurred locally in spite of continuing therapy and involved other parts of the penis. Partial amputation of the penis was performed but further ulceration occurred at the cut ends of the corpora cavernosa in the penile stump. This ulceration healed after radiotherapy.


Idiopathic fat necrosis in the scrotum.

Idiopathic fat necrosis in the scrotum. 2 case of idiopathic scrotal fat necrosis are presented. The aetiology and differential diagnosis are discussed. Trauma, cool temperature and ocean water all appeared to be relevant factors in its production.


Hydronephrosis complicating aortic reconstruction. Prompted by an encounter with a symptomatic case, a study has been made of hydronephrosis complicating operations for aortic reconstruction. Twenty patients operated upon consecutively for occlusive vascular disease and undergoing reconstructions involving the use of synthetic material in the vicintiy of the ureter have been investigated by intravenous pyelography. The incidence of hydronephrosis in pyelograms after a year or more was 10 per cent  of the patients and  5-7 per cent of the ureters at risk. Dilatation, when it arose, was always apparent in the immediate postoperative period, but half of the dilatations evident at that time resolved within a year.


Small doses of subcutaneous sodium heparin in the prevention of deep vein thrombosis after elective hip operations. The efficacy of small perioperative doses of subcutaneous heparin in preventing deep vein thrombosis has been studied in a controlled clinical trial on 64 patients undergoing elective hip surgery. The results indicate that the regimen of sodium heparin used was safe provided that the correct dose is given. It reduced the frequency of postoperative deep vein thrombosis from 37 to 7 per cent.


Postvagotomy dysphagia.

Postvagotomy dysphagia. Following truncal vagotomy some patients develop dysphagia, which rarely can progress to complete obstruction. It has been postulated that haematoma formation in the tissues surrounding the lower oesophagus may lead to peri-oesophageal fibrosis and compression of the lumen of the oesophagus. This has been confirmed by open operation in only a few patients. A case is described in which oesophageal obstruction occurred 3 weeks after a vagotomy and pyloroplasty had been performed.


The relationship of anaemia to gastric secretion more than 15 years after vagotomy and gastro-enterostomy. Iron deficiency anaemia is common following vagotomy and gastro-enterostomy, and this study has shown that all the anaemic patients had low gastric secretion. After correction of their anaemia, gastric secretion was increased, but was still very low, and when these levels were compared with secretion in fit non-anaemic patients it was found that the latter group had a significantly higher secretion, and that a high proportion of them showed evidence of incomplete vagotomy. These results suggest that there is a relationship between the levels of gastric secretion in patients after vagotomy and gastro-enterostomy and the development pf anaemia. It may be that inadequate gastric secretion impairs the release of elemental iron from the diet and its subsequent absorption.


Pancreatic pseudocysts in children: 4 cases from Uganda. Four cases of pancreatic pseudocyst in African children are described. There is some evidence that they followed pancreatitis of unknown aetiology. None had a history of trauma. Three were treated by cystogastrostomy, and the fourth by excision of the cyst.


Gas gangrene of the extremity: the presenting clinical picture in perforating carcinoma of the caecum. This paper reports 2 diabetic patients with perforating carcinoma of the caecum and gas gangrene of the pelvis and right lower extremity in whom the infective process was the main clincial feature.


Pneumatosis cystoides intestinalis with unexplained ascites in Ethiopian patients. Four cases of pneumatosis cystoides intestinalis associated with unexplained ascites in Ethiopian patients are described. The relationship between the two conditions has not previously been reported.


Caecal rupture due to colonic ileus.

Caecal rupture due to colonic ileus. Caecal rupture due to colonic ileus is rare and has a mortality rate of 43 per cent. Three new cases are presented and the 18 previously reported cases are reviewed. The disease has always occurred in association with another illness, has usually afflicted patients over the age of 55 and has only resulted when the caecum was at least 9 cm in diameter. The technique of 'blow-hole' caecostomy, a method for decompressing the distended caecum, is described.


Epidermoid cysts, polyposis coli and Gardner's syndrome. One hundred and ninety-six members of 15 families with Gardner's syndrome were investigated to determine the type of skin cyst that is part of this syndrome. These were shown to be epidermoid cysts and not pilar cysts or steatocystoma multiplex. They were solitary or multiple and seldom large and disfiguring. The skin cysts often occurred before the intestinal polyps were detectable. The presence of epidermoid cysts in children should be an indication for sigmoidoscopy when the child reaches the age of 14 years, and at 3-yearly intervals thereafter up to the age of 30 years, whether or not there is a family history of polyposis coli. At present it is not possible to say if Gardner's syndrome is the same as, or different from, familial polyposis. Until all patients with colonic polyps have a full clinical examination, looking for skin cysts and osteomas, X-rays of the skull and long bones to detect osteomas and dental X-rays for abnormalities of the teeth this question will remain unanswered.


Chronic hydradenitis suppurativa: a report of 9 cases. This paper describes the treatment of 9 patients suffering from hydradenitis suppurativa all of whom were treated by surgical excision. The aetiology, diagnosis and treatment by surgical excision are discussed.


Bilateral extradural haematomas.

Bilateral extradural haematomas. Eleven cases of bilateral extradural haematomas were encountered in a total of 49 cases of extradural haematoma during a period of 4 years among 1000 consecutive cases of acute head injury. Assault was held responsible for 60 per cent of the total head injuries. Most of the patients were seen late; 8 were already unconscious and 5 had dilated fixed pupils. All 11 patients died, 4 soon after admission. Nine cases were found to have associated brain damage at autopsy. In 2 cases bilateral extradural haematomas with compression of the brain were the only intracranial abnormalities. In 4 cases a clost was missed on conventional exploration.


Injury of the facial nerve during surgery of the parotid gland. The notes of 158 patients who had undergone surgery of the parotid gland for benign and malignant disease were studied to discover the circumstances in which the facial nerve might be injured. Limited surgery carried as great a risk of injury to the facial nerve as during extended surgery. Extended surgery provided greater risk of injury to the facial nerve on secondary exploration (71 per cent) than on primary exploration (6-5 per cent). It is concluded that every primary exploratory procedure of the parotid gland should be a formal conservative parotidectomy unless the tumour is obviously malignant.


Pilonidal sinus treated by phenol injection. The method of using phenol injections for the treatment of pilonidal sinus is described in detail. This is a simple, safe and painless method which may be used as a day case procedure. The results are discussed and compare very favourably with the more radical forms of treatment.


The surgical management of ingrowing toenail. A retrospective review has been carried out on 200 randomly selected patients with ingrowing toenail in order to assess the surgical management and its results. There was a predominance of males between the ages of 11 and 30 with an ingrowing toenail. Despite the high recurrence rate following simple avulsion of the toenail, its place in the initial management of the condition is justified. As regards more definitive surgery, total proximal nail bed ablation was found to give the best results. Sepsis at the time of operation neither increased the recurrence rate nor caused severe postoperative sepsis. A surgical management policy for the treatment of ingrowing toenail is outlined and discussed.


Effect of cigarette smoking on fetal breathing movements in normal pregnancies. In 18 women with uncomplicated pregnancies smoking two cigarettes significantly reduced the proportion of the time that fetal breathing movements were present.


Oesophageal foreign bodies.

Oesophageal foreign bodies. Impaction of foreign bodies in the oesophagus was analysed in 54 patients, 45 of whom were children. Of the 45 children 28 were aged 2-4 years. Coins were the most common foreign body in children (27 cases) while in adults a bolus of meat was most common (nine cases). In 41 children there was no predisposing factor, but an underlying mechanism was detected in 88% of the adults. The mechanisms were of three types: oesophageal (stricture), neuromuscular (myasthenia gravis), and extrinsic and mechanical (ankylosing spondylitis). In children most of the foreign bodies were impacted in the upper oesophagus at the cricopharyngeal junction, which is the narrowest part of the oesophagus, while in adults the foreign body was usually impacted at the site of the predisposing lesion or in the lower oesophagus. In all patients oesophagoscopy was performed under general anaesthesia to remove the impacted foreign body. Complications were more frequent in adults, mainly owing to the underlying condition.


A health centre E.C.G. services: its use and abuse. An average of 10-5 E.C.G.s were recorded weekly in a health centre used by 32 general practitioners serving a population of almost 65,000. The main indication for an E.C.G. was chest pain (73%). 47% of the E.C.G.s were abnormal. A change in clinical diagnosis occurred in 28% of cases and in patient management in 16%. A significant number of these changes were unwarranted, however. It is recommended that the E.C.G.s should be recorded by suitably trained nurses and reported by a specially trained general practitioner. Further education of general practitioners in the clinical use of the E.C.G. is required.


Pulled elbow: a study of 100 patients.

Pulled elbow: a study of 100 patients. Pulled elbow is a common condition but may not be recognized by practitioners unaware of its existence. Most of a series of 100 children with this condition were aged 1 or 2 years, and none were over 6 years. An important precipitating factor was the normal recalcitrance of the 1-3 age group. The three children who were over 5 years had all had earlier episodes which may have stretched the annular ligament. The wrist was the most common site of pain after the elbow. A single manipulation was successful in 96 cases but multiple manipulations may be needed.


High blood pressure. detection and treatment by general practitioners. A questionnaire was sent to a 10% random sample of general practitioners in England and Wales on their attitudes to the detection and treatment of hypertension; 62% responded and no further inquiry was made. Their view on detection and criteria for treatment and investigations performed were considered in relation to their background. More of the older practitioners always measured blood pressure and 36% of all practitioners believed that hypertensive patients usually present with symptoms. Altogether 91% thought that strokes could be prevented by treating hypertension, and only 18% reported difficulty in keeping patients on treatment. Older practitioners preferred to measure the distolic pressure using phase five, while the younger preferred phase four. Nearly all doctors were satisfied with their current sphygmomanometers.


Influence of heredity and environment in determination of skinfold thickness in children. Triceps and subscapular skinfold thicknesses were measured in 222 pairs of like-sex twins (78 monozygotic and 144 dizygotic) aged 3-15 years. Log transformations of the measurements were standardized for age and sex and the results used to estimate heritability--that is, the proportion of total variation determined by genetic factors. The overall contribution of non-genetic familial effects was small. There were appreciable differences in heritability between limb and trunk fat and between the sexes and at different ages. Over the age of 10 heritability was high for both sites in boys and girls. In younger children environmental factors contributed more to the variation.


Intravenous treatment with rimiterol and salbutamol in asthma. The bronchodilating efficacies and beta2-adrenoceptor selectivities of rimiterol (0.2, 0.1, and 0.05 mug kg-minus1 min-minus1) and sal-utamol (0.1, 0.5, and 0.025 mug kg-minus1 min-minus1), intravenously infused for one hour, were determined in five patients with chronic asthma. Each drug infusion produced and maintained a dose-related improvement in forced expiratory volune in one second (FEV1). A further increase in FEV1 was produced by inhalation of the same drug by pressurized aerosol at the end of each infusion, which suggested that no resistance had occurred. Similar dose-related increases in heart rate, pulse pressure, and skeletal muscular tremor were produced by each drug. Peak heart rate increases varied greatly between individuals, ranging from 12 to 30 beats/min with the high doses but always less than 10 beats/min with the low doses of each drug. On rimiterol the heart rate reached equilibrium earlier during the infusions and declined more rapidly after they had stopped, thus providing an accurate means for monitoring dosage. Rimeterol with its short half life-a desirable property for an intravenous drug with respect to safety-may prove to be a valuable bronchodilator in severe asthma when intravenous infusions are indicated.


Carbon monoxide yields of cigarettes and their relation to nicotine yield and type of filter. Carbon monoxide (CO) yields of 11 popular brands of British cigarette, two types of cigarette containing tobacco-substitute, and one brand of cigar were measured under standardized conditions. Yields of the conventional cigarettes ranged from 5.0 to 20.2 mg per cigarette (1.3 to 4.7% by volume). The cigar yielded 81.7 mg (10.0%) CO and the two semi-synthetic cigarettes 17.2 (4.2%) and 28.2 mg (6.2%) CO. Puff-by-puff analysis showed an increase in CO concentration as a cigarette is smoked. In brands with nicotine yields over 1.0 mg no relationship was apparent between nicotine yield and CO yield, and the filters of cigarettes in this category did not appear to reduce the CO yield. In the low nicotine cigarettes with ventilated filters there appeared to be some correlation between nicotine yield and CO yield, and these filters were highly effective in reducing CO yield, owing mainly to the ventilation. We suggest that official publication of CO yields might motivate manufacturers to produce cigarettes with lower yields.


Stress in families of children who have ingested poisons. One hundred families of children under 5 years admitted to Cardiff Hospitals after accidentally ingesting poisons were compared with 100 control families matched for socioeconomic class and age and sex of the child. Questioning about five major stress factors  (serious family illness, pregnancy, recent family moves, one parent away from home, anxiety or depression in one or both parents) disclosed significantly more stress in the affected families than in the controls. Thirty of the affected families had more than one major stress factor compared with four of the controls, while 63 of the controls had no major stress factor compared with 24 of the affected families (P less than 0.001). In only four of the affected families was there no stress factor. Fifteen children took poisons in homes other than their own. Unemployment was significantly more prevalent in the affected families than in the general population, though apart from this the socioeconomic backgrounds were similar. There were significantly more accidents and childhood poisonings in the parents and siblings of affected children than in the control families. In 25% of the cases poisoning was with Angiers Junior Aspirin.


Predicting the outcome of stroke: acute stage after cerebral infarction. On admission to hospital during the acute phase of a stroke presumed due to ischaemic infarction in one cerebral hemisphere 93 patients were examined to determine the factors associated with a poor prognosis for immediate survival. The patients particularly at risk were those who were overtly unconscious and those with any combination of impaired consciousness, dense hemiplegia, and failure of conjugate ocular gaze towards the side of the limb weakness. Necropsy evidence suggested that these signs usually indicate infarction of the whole of one middle cerebral artery territory which is often secondary to internal carotid artery occlusion and commonly produces fatal cerebral oedema.


Prognostic significance of acute systolic hypertension after myocardial infarction. The clinical behaviour and mean peak serum aspartate aminotransferase (SGOT) values of 106 patients admitted to a coronary care unit with acute myocardial infarction who displayed acute systolic hypertension were studied. Another 106 normotensive patients with acute myocardial infarction acted as controls. Neither group had established hypertension. The mortality rate, incidence of cardiac failure, major arrhythmias, and mean peak SGOT were significantly greater in the hypertensive group, within which the duration of hypertension was correlated with mean peak SGOT levels--through there was no definite relation between the height of systolic or diastolic pressure and SGOT. Transient systolic hypertension after acute myocardial infarction was therefore associated with a relatively poor prognosis, but our observations suggest that patients with a systolic blood pressure of at least 170 mm Hg might benefit from early hypotensive treatment.


Evidence for HL-A-linked genes in "juvenile" diabetes mellitus. HL-A typing of 150 patients who had developed diabetes mellitus by the age of 30 years showed a significant association with HL-A 8 and W 15. The HL-A genotypes were determined in 17 families in which two or more siblings had this type of diabetes. The zygotic assortment of HL-A haplotypes was found to be significantly disturbed from the expected random pattern, with a reduction in the number of siblings showing no identical haplotypes and an appreciable increase in the number with both haplotypes identical. This appears to be most consistent with the presence of a gene or genes pre-disposing to this type of diabetes at a locus closely linked to the HL-A chromosomal loci. This locus appears to have a fundamental role in the susceptibility to juvenile diabetes.


Nurse therapists in behavioural psychotherapy. Five registered mental nurses (R.M.N.s) were trained over two years to become behavioural psychotherapists for adult neurotic disorders. They achieved results comparable to those obtained with similar patients and methods by psychologists and psychiatrists. Similar results were maintained when over a third year the therapists were seconded to work in four hospitals and a general practice. Patients were satisfied at being treated by nurses. After initial teething difficulties nurse therapists became valuable members of treatment teams during both training and secondment, becoming accepted by most nurses, psychologists, and psychiatrists with whom they came into contact. The training of further nurse therapists would facilitate treatment of many disabled neurotics who would otherwise go without effective treatment. Training nurse therapists takes less time and money than training psychologists and psychiatrists because less of their education is redundant to the skills involved. The pool of R.M.N.s suitable for training is much larger than that of psychiatrists and psychologists. The nurse therapists can be integrated relatively easily into treatment teams. The present nursing structure imposes restrictions on the advancement of clinical nurse specialists and a clinical tree is badly needed parallel with present administrative and teaching hierarchies. An 18-month course in adult behavioural psychotherapy has been recognized by the Joint Board of Clinical Nursing Studies for England and Wales so that nurse therapists seem destined to be a lasting feature of future treatment teams.


Single-dose treatment of gonorrhoea with cotrimoxazole. A report on 1,223 cases. 1,223 ambulant patients with gonorrhoea were each treated with a single dose of eight tablets of cotrimoxazole. 1,069 patients were followed up (794 males and 275 females). Of these, only 46 (4%) failed to respond. Cotrimoxazole in the dosage used was well tolerated by all the patients, with very few side-effects. There was clear evidence that cotrimoxazole did not mask concomitant syphilitic infections; neither did it produce a gonococcal carrier state. The incidence of post-gonococcal non-specific urethritis was 6 per cent. At present cotrimoxazole seems to be the most useful alternative to penicillin in the treatment of gonorrhoea.


Minocycline in the treatment of non-gonococcal urethritis. 108 male patients with non-gonococcal urethritis have been treated with minocycline given as two 100 mg. tablets initially, followed by one tablet twice a day over a period of 6 days (13 tablets). Of 96 patients followed, re-treatment for non-gonococcal urethritis within 3 months was undertaken in ten (10.4 per cent.). The findings are compared with those previously reported in seven series involving six other tetracyclines and with nine other treatment regimens. All of the tetracyclines proved superior to other agents and the best results combined with simplicity of administration were obtained with minocycline. Two patients complained of soreness of the mouth after 1 week but no other side-effects were reported. Minocycline thus gives excellent results in the treatment of non-gonococcal urethritis. In the dosage used it was also successful against gonorrhoea in seven patients treated. It is therefore particularly useful in cases in which gonorrhoea is suspected but not found in the smears or in which the smears cannot be read immediately.


Ampicillin plus probenecid compared with procaine penicillin plus probenecid in the treatment of gonorrhoea. 396 male patients with gonococcal urethritis were treated by one of three treatment schedules. Of 132 patients treated with 2.4 m.u. procaine penicillin plus 2 g. probenecid, 109 were followed. There were three (2.8 per cent) recurrences in the first week and none in the second. Of 132 patients treated with 2 g. ampicillin plus 2 g. probenecid, 112 were followed. There were four (3.6 per cent.) recurrences in the first week and three (2.6 per cent.) in the second (total of 6.2 per cent.). Of 132 patients treated with 3 g. ampicillin plus 2 g. probenecid, 115 were followed. There was one (0.8 per cent.) recurrence in the first week and five (4.4 per cent.) in the second (total of 5.2 per cent.). A close correlation was found between the sensitivities of gonococcal strains to ampicillin and to penicillin. The overall sensitivity pattern of N. gonorrhoeae to penicillin had not changed at The London Hospital since the last report in 1972, but there was further evidence of cross-resistance between penicillin and cotrimoxazole.


Release of (3H)GABA and (14C)glutamic acid from rat cortex slices: the relationship between the tissue pool size and rates of spontaneous and electrically induced release. A constant fraction of the existing tissue pool of (3H)GABA or (14C)glutamic acid was released during electrical stimulation of rat cortex slices. The sum of the amounts of labeled amino acids released spontaneously and by electrical stimulation was constant when stimulated slices were superfused with normal medium or media containing ouabain or a high K+ concentration. The fraction of the total amount released that was attributable to electrical stimulation varied inversely with the amount released spontaneously. Pentobarbital inhibited the accelerated spontaneous release produced by ouabain or high K+ and restored the ability of the slice to respond to electrical stimulation. Electrically induced release was felt to be limited by a theoretical maximum transport velocity of efflux of approximately 5.5% per min.


Loss of active avoidance of responding after lateral hypothalamic injections of 6-hydroxydopamine. After injections of 6-hydroxydopamine (6-OHDA) along the medial forebrain bundle in the lateral hypothalamus, rats failed to acquire a one-way active avoidance response or failed to perform a previously acquired active avoidance response. Such rats, however, acquired a passive avoidance response and a conditioned taste aversion normally. Thus the effect of lateral hypothalamic injections of 6-OHDA was not a total loss of the capacity to acquire or perform conditioned responses, but was a failure to initiate forward movement in the presence of a conditional stimulus. Most of these rats could initiate a similar forward movement to escape from the unconditioned stimulus (foot shock). Failure to acquire or perform the active avoidance response was correlated with the loss of hypothalamic, striatal and forebrain catecholamines produced by lateral hypothalamic 6-OHDA injections. Identical injections of 6-ohda placed along the medial hypothalamus produced a similar loss of regional catecholamines, but medial 6-OHDA injections did not affect active avoidance responding. We interpret this dissociation between loss of catecholamines and the capacity for active avoidance responding to mean that medial 6-OHDA injections did not damage the same catecholaminergic terminal fields as lateral 6-OHDA injections and that the integrity of the terminal fields damaged by lateral 6-OHDA injections is necessary for active avoidance responding.


Sensory and motor representation in the cerebral cortex of the three-toed sloth (Bradypus tridactylus). Cortical sensory receiving areas were studied in 32 specimens of the three-toed sloth, Bradypus tridactylus, using the evoked response technique and barbiturate anaesthesia. Somatotopic organization in the somesthetic first area (S-I) was shown to be similar to that reported in higher mammals. The area devoted to the representation of the forelimb was considerably larger than that for the remaining body parts. The second somatosensory area (S-II), showing bilateral representation without a precise topographical organization, was identified in the rostral portion of the ectosylvian gyrus. Visual and auditory projections, occupying restricted areas, were found along the caudal banks of the ectosylvian fissure. Electrically excitable cortical motor area was explored in 8 animals anesthetized with diallyl barbituric acid in urethane. The motor representation of the various body parts was shown to coincide with the sensory projections, demonstrating the existence in a Eutherian mammal of a sensorimotor amalgam, identical to that described in marsupials. These findings suggest that sloths display a primitive pattern of neural organization, and that the sensory motor amalgam is a generalized form of cortical organization of primitive Therian mammals.


Projection of tooth pulp afferents to the cat trigeminal nucleus caudalis. Unit activity was recorded extracellularly from cat medullary neurons following electrical stimulation of the canine tooth pulp. Response characteristics of the neurons quickly stabilized at specific suprathreshold stimulus intensities but such properties as spike latency, interspike interval and spike density varied systematically as intensity was raised to maximally effective values. Receptive fields were principally unilateral. The majority included both canines and extended into other oro-facial areas. Suppression of a pulpal response could be effected by preceding tooth stimulation with a conditioning stimulus applied to some other point in the receptive field of the responding cell at an appropriate interstimulus interval. In contrast, a pulpal response could be enhanced by presenting two stimuli successively to the same canine at such intervals. Similar enhancing effects followed simultaneous stimulation of spatially segregated loci in a field. The pulp-responsive neurons were localized histologically in, or in the immediate vicinity of, the nucleus caudalis of the spinal trigeminal complex where the possibility of their existence has been questioned previously. Most of the cells were situated along the ventromedial border of the nucleus, a region reported to contain other pain-related neurons with trigeminal fields.


Unit responses to moving stimuli in area 18 of the cat. In paralyzed cats units were recorded from the peripheral projections on area 18. Of 46 cells, 71 percent responded to moving visual stimuli. From this sample 91 percent responded to velocities ranging from 5 to 400 degrees-sec(-1). Within this group, two classes of neurons could be distinguished. The first class had small receptive fields and responded repetitively to a moving grating. They had low spontaneous activity and were located in the superficial cortical layers. Random pattern movement elicited no response. The second class had large receptive fields and higher spontaneous activity. These neurons, found in the deeper layer of the cortex, responded better to slits than to grating. Responses to random pattern motion reached 50-100 percent of grating motion responses. A similar distinction holds for fast movement sensitive neurons of area 17. The identification of both these classes with simple and complex cells is discussed.


Bilateral effects of vestibular nerve stimulation on activity in the lumbar spinal cord. These experiments were designed to study the effects of vestibular nerve stimulation on the activity of hindlimb motoneuron pools. Two techniques were used to stimulate the vestibular nerves of precollicularly decerebrated cats. In one set of experiments the individual semicircular canals were stimulated via bipolar electrodes placed near the canal nerves. In the second series of experiments the whole vestibular nerve was stimulated with an electrode placed on the intradural nerve. Activity in the hindlimb motoneuron pools was ascertained by evoking monosynaptic reflexes in the various hindlimb nerves. Stimulation of the individual semicircular canals produced response patterns that varied with both the vestibular branch being stimulated and the hindlimb nerve being conditioned. Intradural stimulation of the vestibular nerve, on the other hand, evoked similar response patterns in the antagonist ankle flexor and extensor nerves. The most common pattern consisted of facilitation followed by a period of inhibition. Lesions of descending fiber tracts produced results which suggest the presence of a diffuse pathway, involving the recitular formation, which mediates the observed responses. It is suggested that the biphasic response pattern is analogous to the startle response and the function of the responses is discussed in that context.


Biochemical and morphological studies of the short and long term survival of isolated nerve-endings. The respiratory rate, potassium, amino acid, ATP and phosphocreatine content of cortical synaptosomes were measured over periods from one hour to 5 days. Incubation medium or tissue culture medium at 37 degrees C was employed. In suspensions, synaptosomes show diminished levels of all these parameters after 3 or 4 h, but synaptosome beds showed no loss of potassium, ATP or phosphocreatine at this time. Morphologically the synaptosomes showed good preservation of structure during the first 24 h in tissue culture. Respiratory response to electrical pulses was detectable even after 24 h in culture when basal respiration was low.


Dopamine metabolism in characterised neurones of Planorbis corneus. A sensitive chromatographic procedure was used to study the metabolism of [14C]tyrosine, [3H]DOPA and [3H]dopamine in 3 defined cell-types situated in the nervous system of Planorbis corneus. One of the cell-types contains dopamine (GDC), the other serotonin (GSC) and the other neither amine (GC). The GDCs metabolise [14C]tyrosine to form DOPA and dopamine while the other two cells lack this ability. In contrast, the GDCs and the GSC, but not the GCs, metabolise [3H]DOPA to form dopamine. In addition the GDCs incorporate radioactivity from [3H]DOPA into DOPAC, homovanillic acid and methoxytyramine. After incubation of cells in [3H]dopamine, only the GDCs metabolise it to form DOPAC, homovanillic acid and methoxytyramine. In no instance did the GDCs form significant amounts of noradrenaline from the incorporated radioactive substances. These results, together with data on the amine histochemistry of the individual cell-types following pretretment of animals with drugs known to affect specific enzymes in the synthesis of amine transmitter substances, clearly demonstrate that the GDCs alone have the enzymes requisite for the biosynthesis and catabolism of dopamine, but not noradrenaline.


The effects of monocular deprivation on synaptic terminals in the visual cortex of rabbits. A quantitative electron microscopic study. The effect of prolonged (7 month) monocular deprivation (right eye sutured) on the density of synapses (NA) and the number of synaptic vesicles (Nves) in the visual cortex of rabbits is studied. The results can be summarized as follows: (1) No changes (NA and Nves) are observed in the non-deprived hemisphere (visual areas I and II, motor cortex) as compared to control animals. (2) NA has not changed, as compared to control animals, in the binocular field of the deprived visual cortex. (3) A significant rise in NA, as compared to control animals, is observed in the monocular field of area I and in the motor cortex of the deprived cortex. This rise is similar to that found after recovery from prolonged dark rearing. (4) The increase in NA is mainly restricted to the laminae I-II, indicating that, most likely, we are not dealing with an increase in specific visual afferents. (5) The deprived visual cortex shows a significant decrease (16%) in NVes. This decrease is less pronounced than after dark rearing (40%). This probably points to the fact that eye suturing does not fully prevent light penetration. The results are discussed in the light of recent discussions on the plasticity of synapses and the effect of retinal input on the development of the visual system.


Undershoots following stimulus-induced rises of extracellular potassium concentration in cerebral cortex of cat. Extracellular potassium activity (ak) was recorded with potassium-sensitive electrodes in the sensorimotor cortex of cats. Resting activity was 2.8--3.4 mEquiv/l. Electric stimulation of the cortical surface and the nucleus ventroposterolateralis of the thalamus brought about an increase in aK followed by an undershoot and return to normal value. The lowest observed value of aK was 2.1 mEquiv./l. Size and duration (range 0.5--4 min) of the undershoots of aK increased with increasing peak amplitudes of the preceding rise in aK. Following the rise in aK, a period of reduced neuronal activity was observed which usually shorter lasting than the decrease in extracellular aK. An undershoot of aK and a concomitant reduction of neuronal discharge frequency can also occur in immediate response to antidromic stimulation of the pyramidal tract. To compare the K+ redistribution at normal and reduced levels of aK electrophoretic K+ signals were produced with constant current pulses from a proximate KCl-filled capillary. Both amplitudes and half times of decay of these K+ signals were found to decrease during the phase of poststimulatory undershoot in aK (19 and 23% respectively). It is suggested that an activated reuptake of potassium contributes to the decrease in extracellular aK in addition to inhibitory processes.


Inhibitory and excitatory effects of CNS depressants on invertebrate synapses. (1) The effects of pentobarbital were studied on the membrane properties and synaptic activity of crustacean neuromuscular junction preparations and molluscan neurons. (2) Pentobarbital selectivity depressed in a dose-dependent, reversible manner the exciatory postynaptic potentials (EPSPs) recorded at crustacean neuromuscular junctions without altering either inhibitory postsynaptic potentials (IPSPs) or post-synaptic membrane properties. (3) Pentobarbital depressed cholinergic EPSPs recorded in an identified molluscan neuron and depressed the depolarizing phase of biphasic PSP without affecting the hyperpolarizing phase of the BPSP on the same cell. Facilitation of the EPSP was not affected. (4) Pentobarbital did not appreciably alter the reversal potentials of the EPSP and IPSP. (5) Low concentrations of pentobarbital did not alter the appearance of spontaneously occurring IPSPs, while high concentrations changed the pattern of regular IPSP input to an irregular, burst-like pattern. (6) Pentobarbital and 5 other CNS depressants (cholralose, chloroform, ethanol, and urethane) increased the excitability and altered the current--voltage relations of a cell whose membrane properties have been proposed as a model of presynaptic terminal membranes. The effects were dependent on the species of external divalent cation present. (7) The results in these invertebrate systems may provide insight into the cellular basis of the depressant and excitatory effects of these agents.


Neurochemical and morphological changes during the development of cobalt-induced epilepsy in the rat. Following the implantation of cobalt-gelatine pellets into the frontal cortex, epileptiform spikes in both primary and secondary foci developed and reached a peak between 7-12 days post implantation. Histological examination showed a necrotic lesion with terminal and fibre degeneration in brain areas connected with the frontal cortex. Golgi staining at 60 days showed a loss of pyramidal cells in the primary focal area. In the lesion and primary focal areas GABA, glutamate and aspartate were significantly reduced between 5--10 days post implantation. No changes in glutamine and glycine were found in either the lesion or pulmonary focus. No changes in amino acid content were found in the secondary focus or in glass implanted controls at any time. In cobalt-treated rats there were significant reductions in the transmitter related enzymes, glutamate decarboxylase, acetylcholinesterase, choline acetyltransferase and aromatic amino acid decarboxylase in the lesion area and primary and secondary foci at 4--8 days post implantation. Levels of these enzymes had recovered to normal by 24 days. Lactate dehydrogenase was reduced only in the lesion area. Beta-Galactosidase was reduced in the lesion area at 4 days but subsequent rose rapidly paralleling increasing gliosis around the lesion. It is concluded that cobalt-induced epilepsy is associated with relatively selective loss of neuronal tissue and provides a useful model for further investigation relevant to clinical epilepsy.


A comparison of the energy metabolism of two breeds of hens and their cross using respiration calorimetry. 1. The maintenance energy requirement of the Black Australorp, White Leghorn and Black Australorp times White Leghorn hen was 911, 765 and 885 kJ/d respectively and availability of metabolisable energy of the diet was 79, 84 and 92%. 2. Heat production, after 30 h of starvation, was 311, 395 and 387 kJ/kg W0-75/d for the Australorp, Leghorn and crossbred, respectively. 3. It was calculated that availability of metabolisable energy was 51% for protein and 96% for fat retention. 4. Water consumption was significantly higher for the Black Australorp at the mean level of food intake for all hens, and increased more rapidly per unit intake than was observed for the other two breeds.


Studies of the energy and protein requirements of the growing guinea-fowl. 1. Guinea-fowl of both sexes and female chickens were fed from 1 to 12 weeks on diets the energy concentration of which was constant at either 2-6, 2-9 or 3-2 Mcal/kg (10-8, 12-1 or 13-4 MJ/kg) while the calorie to protein ratios were changed, for some groups, from 124 to 157 or 200 at 4 and 8 weeks. 2. Guinea-fowl, but not chickens, were unable to overconsume when the protein concentration was low with the result that the body fat content was not reduced when the protein concentration was increased. 3. In the second trial the ME level of the diets was fixed at 12-6 MJ/kg while the protein content was varied, from 21 to 28% in the diets fed to 6 weeks of age and from 15 to 24% in those fed from 6 to 12 weeks. 4. It is concluded that for the growing guinea-fowl the diet should contain 12-6 MJ ME/kg, the protein concentration reducing from 24 to 26% in the period 0 to 4 weeks to 19 to 20% in the period 4 to 8 weeks and to 16% or less in the period 8 to 12 weeks.


Localisation and characterisation of egg shell porphyrins in several avian species. 1. Electron microscopy, infra-red analysis and histochemical techniques have been used to determine the site of pigment deposition, the cellular localisation of pigment and the type of pigment precipitated in the egg shells of quail, White Leghorn, Brown Ranger and Black-Headed gull. 2. Transfer of pigment occurs via the surface epithelial cells of the shell gland. 3. Porphyrins are probably synthesised in the blood. 4. Possible pigment deposition mechanisms are discussed.


Studies on the isthmus region of the somestic fowl. The isthmus extends from the aglandular zone, which delimits it from the magnum, to the tubular shell gland, which to the naked eye is marked by a distinct colour change from off-white to brown. 2. The surface epithelium comprises three cell types, ciliated, non-ciliated and mitochondrial, of which only the non-ciliated cells contribute towards the carbohydrate moiety of the shell membranes. 3. The gland cells are distinctive, containing granules of variable electron density, variations also occurring within individual granules. 4. Although two types of gland cell have been observed, they may merely represent different phases of development. 5. In the type 1 cell, the rough endoplasmic reticulum and Golgi complex are typical of the normal protein secreting cell; in the type 2 cell the RER is sparse, dilated and filled with intracisternal granules while the Golgi complex is likewise distended.


Reproductive activity of broiler hens subjected to restricted feeding during rearing. Restricting the food intake of broiler hens during the rearing phase resulted in a 10% improvement in the rate of lay of hatchable eggs compared with fully fed controls. 2. The restricted hens had longer, heavier oviducts, a faster rate of growth of ovarian follicles and a greater spread of oviposition times throughout the day. 3. It is suggested that these changes may explain the persistence of improved production after compensatory weight gain, even into a second production year.


Macromolecular composition of fast, slow and cardiac muscles of chick during incubation. Total muscle mass increases about five-fold in fast (anterior latissimus dorsi: ALD) and slow (posterior latissimus dorsi: PLD) muscles and 30-fold in cardiac muscle between the 12th and 20th d of incubation. 2. Increase in muscle protein does not parallel the rise in muscle RNA. 3. The DNA concentration of the ALD muscle decreases while that of the heart and PLD muscle show an increase between 8 and 12 d and a steady decrease thereafter. 4. The increase in glycogen concentration is greater in heart than in ALD and PLD up to the 20th d; 1 d after hatching, ALD has more glycogen than PLD.


Amino acid requirements of growing chickens. 1. Using 18% protein diets (N times 6-25), consisting mainly of conventional ingredients of known amino acid composition, the amino acid requirements as percentages of diet and of dietary protein respectively for broiler chickens between 14 and 28 d of age were found to be: threonine 0-50-0-52% of diet (2-8-2-9% of dietary protein); glycine 0-48-0-50 (2-7-2-8); valine 0-69-0-71 (3-8-3-9); methionine+cystine 0-58 (3-2); isoleucine smaller than 0-48 (smaller than 2-7); leucine smaller than 1-05 (smaller than 5-8); tyrosine+phenylalanine 1-09-1-12 (6-1-6-2); lysine 0-87 (4-8); histidine smaller than 0-34 (smaller than 1-9); arginine smaller than 0-76 (smaller than 4-2); tryptophan smaller than 0-14 (smaller than 0-78). 2. Values found were in general lower than those determined using diets consisting entirely of purified amino acids and the reasons for this are discussed.


Amino acid requirements of the young turkey: lysine and arginine. The arginine and lysine requirements for maximum growth of the 3-week-old turkey, determined in a factorial manner, were 1-75% arginine and 1-55% lysine. 2. It is demonstrated that the arginine required to support a growth rate of about 20 g/d is similar in turkeys and chicks, suggesting that the efficiency with which dietary arginine was utilised for growth is similar in both species.


Distribution of labelled testosterone in Japanese quail using autoradiography of whole body sections. Auto radiography offers a simple method of giving preliminary information about the metabolism in vivo of steroids. 2. In Japanese quail injected testosterone is metabolised mainly in the gastro-intestinal tract.


Effect of fasting and parathyroid hormone injection on plasma 45Ca concentrations in rats. Young male rats were administered 45Ca 5 days to 2 weeks prior to use. All rats were either parathyroidectomized (PTX) or thyroparathyroidectomized (TPTX) and given several days to recover from surgery. The first group of rats were maintained on a 12 h dark-fed and 12 h light-fasted daily cycle. The remainder of the rats were used for parathyroid hormone (PTH) studies (0.1-0.6U/g body weight) following which blood samples were obtained from the tail for 1 to 6 h. Two groups of these rats were bilaterally nephrectomized 18 h before PTH injection. Two contrasting results were obtained: in PTX (or TPTX) rats maintained on the closely regulated food and light regime, plasma 45Ca concentrations rose markedly each day at the start of the fasting period and then fell slowly. Total plasma calcium values fell throughout the fasting period. A similar rise and fall was also observed in 45Ca values of rats experimentally fasted after being maintained with food continuously available. In contrast, in all PTX or TPTX rats, PTH injections was followed by an equal rise in both plasma calcium and 45Ca values so that for the first few hours plasma 45Ca specific acitvity was unchanged. These data are consistent with the concept of a bone fluid compartment (BFC) separated by a cellular interface from the primary extracellular fluid space (ecf). It is postulated that through this cellular interface calcium is actively "pumped" from the BFC to the ECF. The rise in plasma 45Ca values at the start of fasting is explained on the basis of decreased entry of stable calcium from the gastrointestinal tract and a continued movement of calcium and 45Ca from the BFC to the ECF. The concomitant increase in plasma calcium and 45Ca during the first few hours after PTH injection is explained by a rapid action of PTH to increase the rate of calcium movement from BFC to ECF by its action at the cellular interface, without altering 45Ca specific activity until such time as dissolution of bone crystals is required as a supply of calcium.


The absorption and scattering of light in bovine and human dental enamel. The reflectance and transmission of thin slabs of dental enamel has been measured at all wavelenghts between 220 and 700 nm by means of an integrating sphere. From the results the true scattering and absorption coefficients have been computed. The theoretical model used is an extended two-flux model, which is presented and discussed. The absorption spectrum of the dissolved organic component of enemel was also determined. An absorption peak at 270 nm is common to all the spectra. This peak in the bovine enamel spectrum is about three times as high as in the spectrum of human enamel. The peak of the dissolved material is about as high as the peak of the corresponding enamel. Hence it is concluded that the organic component, presumably aromatic amino acids, is responsible for most or all of the observed optical absorption.


The bending stiffness of the human tibia. The bending of isolated human cadaveric tibiae in the antero-posterior and medio-lateral planes was studied. It was found that the mean bending stiffness in the antero-posterior plan was 5.989 Nm/mm and in the medio-lateral plane 3.588 Nm/mm.


A precision microdissection procedure for undecalcified bone thin sections. A procedure is described for removing osteons from undecalcified, thin sections of bone. The method involves the use of a microdrilling machine in combination with a micromanipulator. The procedure allows a substantial reduction in the time required for microdissection over previously described methods while permitting the irregular contours of osteons to be followed with precision.


Daily fluctuations in plasma calcium, phosphate, and their radionuclide concentrations in the rat. Daily fluctuations in plasma calcium, phosphate and their radionuclides (injected 5 or more days previously) were determined in rats maintained on a closely controlled feeding and light schedule. Male rats (150-300 g) were trained to a 7a.m.-7p.m. "light" schedule with food available 9 p.m. to 9 a.m. All prarmeters dropped rapidly at the start of each feeding period and then rose during the day. The daily changes in radionuclide concentrations were several orders of magnitude greater than for the stable ions. Continuous access to food produced an earlier fall (5 p.m.) in all plasma values. In thyroidectomized rats (with parathyroid transplants) plasma calcium and phosphate remained relatively constant during the 24 h period. If the time of availability of food was moved 6 h earlier (no change in light cycle), the drop in these plasma values also occurred 6 h earlier. Closer examination of these daily changes indicated that all values fell at least 1 h prior to feeding. In fasted rats, plasma calcium and phosphate concentrations fell as usual; however, 45Ca and 32P rose instead of falling. It was concluded that, in normal rats, changes in endogenous calcitonin secretion may actually increase rather than decrease daily pertubations of plasma calcium and phosphate. Daily changes in these values are influenced by a condition reflex developed due to the feeding habits of the rats. Finally, it is suggested that intestinal hormones rather than calcium may be the primary control of calcitonin secretion, and that the gastrointestinal tract plays a major role, in addition to absorptive activity, in both calcium and phosphate homeostasis.


Ulnar nerve injury associated with anaesthesia. Information regarding 35 patients who developed signs and symptoms of lesions in the ulnar nerve during the post-anaesthetic period, has been reported. The pertinent anatomical and physiological factors in the aetiology of compression neuropathy of the ulnar nerve have been summarized. The use of electromyography and nerve conduction studies has been discussed in relation to localizing the site, following the progression, estimating the severity of a lesion and helping to differentiate between a recent or a pre-operative lesion. Lesions of the ulnar nerve continue to occur in patients who receive an anaesthetic. In our cases the severity of the lesions was not related to age, sex, type of operation or anaesthetic or the duration of the anaesthetic. Compression neuropathies of the ulnar nerve occurred more commonly in males than females. They may lead to a prolonged disability. Preventive measures and the importance of adequate follow-up have been discussed briefly.


Operating room air pollution: influence of anaesthetic circuit, vapour concentration, gas flow and ventilation. Atmospheric halothane was sampled from three selected operating theatres and anaesthetic rooms during the middle of operating sessions. Two of the operating theatres studied were ventilated with total air exchange once every six minutes; the third operating theatre had no ventilation. End-tidal samples were obtained from anaesthetists. Halothane vapour concentrations were analysed by gas-liquid chromatography. The effect of commonly used anaesthetic circuits on the level of contamination in the ambient atmosphere was studied. Concentrations of halothane vapour in the theatre atmosphere were found to vary with sampling site, anaesthetic circuit used, total gas flow and vapour concentration, the scavenging system employed and the efficiency of ventilation system. Although the ventilation system considerably reduced the level of halothane in the operating room atmosphere, it did not totally eliminate the contaminating vapour. A significant reduction in operating-room pollution was obtained by use of simple scavenging equipment. Scavenging of anaesthetic vapours outside the operating room led to 97.3 per cent reduction of overall mean concentration of halothane in the operating room atmosphere and reduction of 72 per cent in end-tidal samples of anaesthetists, with the Magill semiclosed circuit. The implications of these findings are discussed.


A comparison of memory under three methods of anaesthesia with nitrous oxide and curare. Sixty-three volunteer patients participated in an investigation disigned to evaluate memory of the surgical experinece with three different methods of balanced nitrous oxide-curare anaesthesia. Two of the methods (Liverpool and Roosevelt protocols) used thiopentone for induction but did not utilize any neuroleptic drug, while the third (Diazepam protocol) used the tranquilizer diazepam in combination with morphine for both premedication and induction. In general, the results suggest that all three variations are successful in producing anaesthesia and that patients have no recall of the major portion of the surgical procedure. The major differences among the groups were exhibited in the post-operative periods. These findings suggest that diazepam affects the emotional quality associated with memory and thus aids the patients by reducing both the incidence of noxious psychological reactions and the possibility of severe emotional trauma. Finally, the findings also suggest the importance of using a narcotic analgesic as part of nitrous oxide-curare anaesthesia.